Packaging tray

ABSTRACT

A panel holding portion of a packaging tray according to an aspect of the present invention includes a holding recess, a panel supporting portion, a supporting foot, a panel pressing portion, and a tray supporting portion. In a state in which a display panel is held in the holding recess, a top tier tray is stacked above the packaging tray, and a bottom tier tray is stacked below the packaging tray, the supporting foot includes a first contact surface that is in contact with the tray supporting portion of the bottom tier tray, the panel pressing portion includes a second contact surface that is in contact with the display panel held in the bottom tier tray, and the tray supporting portion includes a third contact surface that is in contact with the first contact surface of the top tier tray.

TECHNICAL FIELD

An aspect of the present invention relates to a packaging tray.

The present application claims priority based on Japanese Patent Application No. 2017-086296 filed in the Japan Patent Office on Apr. 25, 2017, the entire contents of which are incorporated herein by reference.

BACKGROUND ART

Existing packaging trays for packaging display panels, such as liquid crystal panels, are used to convey the display panels. During the conveyance of display panels, breakage and damage to the display panels can be reduced by holding the display panels in the packaging trays made especially for the display panels and conveying the display panels in the packaging trays. In addition, when the packaging trays are packaged in a state of being stacked in a plurality of tiers, advantageous effects such as a reduction in the amount of packaging material usage and the downsizing of packages can be attained.

PTL 1 discloses a packaging tray including a holding portion for holding a liquid crystal panel and a protrusion that protrudes from the back surface side of the holding portion. PTL 1 describes that coming off of the liquid crystal panel is suppressed because, when the packaging trays are stacked in a plurality of tiers, the protrusion of an upper tier packaging tray press the liquid crystal panel held in a lower tier packaging tray.

PTL 2 discloses a packaging tray including a holding recess for holding a liquid crystal panel and position determining portions that are provided around the holding recess and that determine the stacking positions of other packaging trays that are placed above and below the packaging tray. PTL 2 describes as follows. The packaging tray further includes a panel pressing portion, and the panel pressing portion comes into contact with a peripheral portion of the liquid crystal panel held in the lower tier packaging tray when the packaging trays are stacked in a plurality of tiers. Thus, the liquid crystal panels are held stably, which enhances the safety of the liquid crystal panels during transportation.

CITATION LIST Patent Literature

-   PTL 1: Japanese Unexamined Patent Application Publication No.     2008-100743 -   PTL 2: Japanese Unexamined Patent Application Publication No.     11-198938

SUMMARY OF INVENTION Technical Problem

However, the trays described in PTL 1 and PTL 2 are configured in such a way that, when the trays are stacked in a plurality of tiers, the liquid crystal panel held in one of the trays directly receives the load of trays placed above the one of the trays. Therefore, if the load exceeds the strength of the liquid crystal panels, defects such as fracture and chipping in the liquid crystal panels may occur.

In recent years, the mechanical strength of liquid crystal panels has tended to decrease with the thickness reduction of liquid crystal panels. Movement of the liquid crystal panels in trays due to vibration, the tilt of packages, and the like during transportation is undesirable because the movement may damage the panels. Therefore, liquid crystal panels need to be fixed to trays with appropriate force. Thus, even in a state of being stacked in a plurality of tiers, packaging trays are required to protect liquid crystal panels while fixing liquid crystal panels with appropriate force that is not likely to damage liquid crystal panels.

An aspect of the present invention has been made for solving the above problem, and an object of the aspect of the present invention is to provide a packaging tray capable of reducing the occurrence of defects in display panels when a plurality of packaging trays are stacked.

Solution to Problem

To achieve the object, a packaging tray according to an aspect of the present invention is capable of holding at least one display panel and is stackable in a plurality of tiers. The packaging tray includes at least one panel holding portion. The panel holding portion includes a holding recess that holds the display panel, a panel supporting portion that protrudes to a position above a bottom plate of the holding recess and that comes into contact with a lower surface of the display panel to support the display panel, a supporting foot protruding to a position below the bottom plate of the holding recess, a panel pressing portion provided in the supporting foot, and a tray supporting portion provided on an upper surface side of the supporting foot. In a state in which the display panel is held in the holding recess, a top tier tray having a shape of the packaging tray is stacked above the packaging tray, and a bottom tier tray having the shape of the packaging tray is stacked below the packaging tray, the supporting foot includes a first contact surface that is in contact with the tray supporting portion of the bottom tier tray, the panel pressing portion includes a second contact surface that is in contact with the display panel held in the bottom tier tray, and the tray supporting portion includes a third contact surface that is in contact with the first contact surface of the top tier tray.

In the packaging tray according to an aspect of the present invention, the panel supporting portion may be disposed at a position where the panel supporting portion comes into contact with a peripheral portion of the display panel from below, and the panel pressing portion may be disposed at a position where the panel pressing portion comes into contact with the peripheral portion of the display panel from above.

In the packaging tray according to an aspect of the present invention, the second contact surface may be provided so as to incline with respect to the first contact surface and may come into contact with an upper corner of the peripheral portion of the display panel.

In the packaging tray according to an aspect of the present invention, the panel pressing portion may further include a first step portion provided between the first contact surface and the second contact surface, and the second contact surface may come into contact with an upper surface of the peripheral portion of the display panel.

In the packaging tray according to an aspect of the present invention, the supporting foot may further include a side wall surface rising from the second contact surface toward the panel supporting portion, and a junction of the second contact surface and the side wall surface may be rounded into a curved surface.

In the packaging tray according to an aspect of the present invention, the panel pressing portion may further include a noncontact surface that is continuous from the second contact surface and that does not come into contact with the display panel and a second step portion that is provided between the second contact surface and the noncontact surface.

In the packaging tray according to an aspect of the present invention, a shape of the supporting foot as seen in a normal direction of the bottom plate may be a rectangle, and corners of the rectangle that is the shape of the supporting foot may be rounded into curved surfaces.

In the packaging tray according to an aspect of the present invention, an outer dimension of an upper side of the tray supporting portion may be relatively large, and an outer dimension of a lower side of the tray supporting portion may be relatively small.

Advantageous Effects of Invention

With an aspect of the present invention, the occurrence of defects in the liquid crystal panels when a plurality of packaging trays are stacked can be reduced.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a packaging tray according to a first embodiment.

FIG. 2 is a perspective view illustrating a state in which a plurality of packaging trays are stacked.

FIG. 3 is a perspective view illustrating a state in which a stack of the packaging trays is packaged in a bag.

FIG. 4 is a perspective view illustrating a process of packaging the packaging trays in a box.

FIG. 5 is a magnified view illustrating an area indicated by reference sign A in FIG. 1.

FIG. 6 is a sectional view of the packaging tray.

FIG. 7 is a sectional view illustrating a state in which three packaging trays are stacked in tiers.

FIG. 8 is a perspective view of a supporting foot as seen from the lower surface side.

FIG. 9 illustrates a function of a first curved surface portion.

FIG. 10 illustrates a problem with a packaging tray of a first comparative example.

FIG. 11 is a sectional view of a packaging tray according to a second embodiment.

FIG. 12 is a sectional view illustrating a state in which three packaging trays are stacked in tiers.

FIG. 13 is a perspective view of a supporting foot as seen from the lower surface side.

FIG. 14 illustrates a problem with a packaging tray of a second comparative example.

FIG. 15 is a perspective view of a panel pressing portion of a packaging tray according to a third embodiment as seen from the lower surface side.

FIG. 16 illustrates a function of a second step portion.

DESCRIPTION OF EMBODIMENTS First Embodiment

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 10.

FIG. 1 is a perspective view of a packaging tray of the first embodiment.

For easy view of each component, some components are illustrated at different scales in each following figure.

Hereinafter, the embodiments will be described on the assumption that a liquid crystal panel P is placed from above and held in a packaging tray 1, an opening side of a panel holding portion 2 for holding the liquid crystal panel P is referred to as the upper side of the packaging tray 1, and the opposite side from the opening side of the panel holding portion 2 is referred to as the lower side of the packaging tray 1.

The lateral direction of the panel holding portion 2 corresponds to the X direction, the longitudinal direction of the panel holding portion 2 corresponds to the Y direction, and the depth direction of the panel holding portion 2 corresponds to the Z direction.

As illustrated in FIG. 1, the packaging tray 1 according to the present embodiment includes four panel holding portions 2 arranged in two rows and two columns and can hold four liquid crystal panels P (display panels). The packaging tray 1 has a substantially rectangular planar shape as seen in the normal direction of the plane in which four panel holding portions 2 are arranged (Z direction). The liquid crystal panel P is a small liquid crystal panel that includes a panel body and a circuit board for driving the panel body and that is for use in mobile electronic equipment, for example. The packaging tray 1 is stackable in a plurality of tiers.

The packaging tray 1 is made up of, for example, a molded item produced by vacuum forming or pressure forming a thermoplastic synthetic resin sheet. That is, the packaging tray 1 is produced by heating to soften a thermoplastic synthetic resin sheet, by applying pressure (vacuum pressure or air pressure) to the softened thermoplastic synthetic resin sheet to push the thermoplastic synthetic resin sheet into a mold, and by transferring the shape of the mold surface to the thermoplastic synthetic resin sheet. Examples of thermoplastic synthetic resin sheets are foamed sheets or non-foamed sheets of polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET), polyethylene (PE), and the like. The thickness of a thermoplastic synthetic resin sheet is selected appropriately, for example, within a range of 0.5 mm to 2 mm.

Here, one example of the methods for packaging a plurality of liquid crystal panels P using the packaging trays 1 will be described.

First, as illustrated in FIG. 2, the packaging trays 1 holding the liquid crystal panels P in the panel holding portions 2 are stacked in a plurality of tiers. In addition, an empty packaging tray 1 that does not hold any liquid crystal panels P is placed in the top tier. Hereinafter, a stack of the packaging trays 1 stacked in a plurality of tiers will be referred to as a tray stack 3.

Next, as illustrated in FIG. 3, the tray stack 3 is placed in a bag 5. The bag 5 is formed of, for example, a resin such as polyethylene. Subsequently, an opening portion of the bag 5 is folded and then fastened with an adhesive tape piece 6.

Next, as illustrated in FIG. 4, the tray stack 3 placed in the bag 5 is wrapped with an inner sleeve 7 therearound.

Next, two sets of the tray stacks 3 wrapped in the inner sleeves 7 are placed into the inside of a tubular outer sleeve 8. The inner sleeve 7 and the outer sleeve 8 are made of corrugated board, for example. The corrugated board may be made of paper or plastic materials.

Next, the tray stacks 3 wrapped in the inner sleeves 7 and the outer sleeves 8 are placed in a box 9 in a plurality of tiers such as two tiers. The box 9 is a carton, for example. Top flaps of the carton are closed and sealed with an adhesive tape piece 10 to complete the packaging of the liquid crystal panels P. Although the corrugated carton is used here as the box 9 for holding the tray stacks 3, a returnable box of a synthetic resin or the like may be used.

It is not necessary that all of the above-described packaging materials, that is, the bag 5, the inner sleeve 7, the outer sleeve 8, and the box 9 be used. Packaging without some of the above-described packaging materials is possible. However, it is preferable that at least one of the bag 5 and the box 9 be used as packaging materials in order to hold the packaging trays 1 stacked in a plurality of tiers to avoid collapse of the packaging trays 1.

Hereinafter, the configuration of the packaging tray 1 will be described in detail.

FIG. 5 is a magnified view illustrating an area indicated by reference sign A in FIG. 1, that is, one panel holding portion 2.

FIG. 6 is a sectional view of the packaging tray 1 taken along line VI-VI in FIG. 5.

FIG. 7 is a sectional view illustrating a state in which three packaging trays 1 are stacked in tiers.

The packaging trays 1 stacked in three tiers have the same configuration. The configuration will be described by focusing on mainly the packaging tray 1 in the middle tier of the three-tier packaging trays 1, for convenience of description. The packaging tray 1 in the top tier is referred to as a top tier tray 1T, and the packaging tray 1 in the bottom tier is referred to as a bottom tier tray 1B.

As illustrated in FIGS. 5 to 7, the panel holding portion 2 includes a holding recess 12, a panel supporting portion 13, a supporting foot 14, a panel pressing portion 15, and a tray supporting portion 16. The holding recess 12, the panel supporting portion 13, the supporting foot 14, the panel pressing portion 15, and the tray supporting portion 16 are made up of a molded item of a thermoplastic synthetic resin sheet, as described above, and all are formed into a single body. The panel holding portion 2 has a substantially rectangular planar shape as seen from above (Z direction).

The holding recess 12 includes a bottom plate 18 disposed at a position lower than an upper surface 13 a of the panel supporting portion 13 (described below) and holds the display panel P. When the liquid crystal panel P is held in the packaging tray 1, the bottom plate 18 is not in contact with the liquid crystal panel P. The bottom plate 18 extends in the longitudinal direction of the panel holding portion 2 (Y direction) and has recesses and protrusions arranged alternately in the lateral direction of the panel holding portion 2 (X direction). Thus, the warpage of the packaging tray 1, which tends to occur when the bottom plate 18 is a flat plate, is less likely to occur.

The panel supporting portion 13 protrudes to a position above the bottom plate 18 of the holding recess 12 and supports the liquid crystal panel P in a state of being in contact with the lower surface of the liquid crystal panel P. The panel supporting portion 13 extends along four sides of the holding recess 12 so as to surround the perimeter of the holding recess 12. The panel supporting portion 13 is disposed at a position where the panel supporting portion 13 comes into contact with a peripheral portion of the liquid crystal panel P from below, when the liquid crystal panel P is held in the packaging tray 1. The edge of the upper surface 13 a of the panel supporting portion 13 on the holding recess 12 side forms a curved surface 13 r (rounded surface) having a predetermined radius of curvature.

The supporting foot 14 protrudes to a position below the bottom plate 18 of the holding recess 12. Thus, a space on the upper surface side of the supporting foot 14 is a recess on the side of the panel supporting portion 13. For example, when the packaging tray 1 is placed on a table, a lower surface 14 b of the supporting foot 14 comes into contact with the table and supports the entire packaging tray 1. Moreover, in a state in which the packaging trays 1 are stacked in a plurality of tiers, the lower surface 14 b of the supporting foot 14 is in contact with the tray supporting portion 16 (described below) of the bottom tier tray 1B. Hereinafter, the lower surface 14 b of the supporting foot 14 that comes into contact with the tray supporting portion 16 will be referred to as a first contact surface 14 b. That is, the supporting foot 14 includes the first contact surface 14 b to be in contact with the tray supporting portion 16 of the bottom tier tray 1B.

The panel pressing portion 15 is provided at the edge of the supporting foot 14 on the holding recess 12 side of the bottom tier tray 1B. In the state in which the packaging trays 1 are stacked in a plurality of tiers, the panel pressing portion 15 is disposed at a position where the panel pressing portion 15 comes into contact with, from above, the peripheral portion of the liquid crystal panel P held in the bottom tier tray 1B. A lower surface 15 b of the panel pressing portion 15 comes into contact with the liquid crystal panel P. Hereinafter, the lower surface 15 b of the panel pressing portion 15 that comes into contact with the liquid crystal panel P will be referred to as a second contact surface 15 b. That is, the panel pressing portion 15 includes the second contact surface 15 b to be in contact with the liquid crystal panel P.

The second contact surface 15 b is provided so as to incline at an angle θ of 45° to the first contact surface 14 b of the supporting foot 14. The second contact surface 15 b comes into contact with an upper corner of the peripheral portion of the liquid crystal panel P. The angle θ formed by the first contact surface 14 b and the second contact surface 15 b is not necessarily 45 degrees and may be set at any appropriate angle.

The tray supporting portion 16 is formed in a recess on an upper surface 14 a side of the supporting foot 14. The tray supporting portion 16 is made up of a protrusion that protrudes from a side plate 14 c of the supporting foot 14 in the longitudinal direction of the panel holding portion 2 (Y direction). The shape of the tray supporting portion 16 as seen in the longitudinal direction of the panel holding portion 2 (Y direction) is substantially semicircular. A linear part of the semicircle is at an upper position, and a curved part of the semicircle is at a lower position.

As illustrated in FIG. 6, the outer dimension W1 of the upper side of the tray supporting portion 16 is relatively large, and the outer dimension W2 of the lower side is relatively small. The outer dimension of the tray supporting portion 16 is defined as the width in the horizontal direction of the tray supporting portion 16, when the tray supporting portion 16 is seen in the longitudinal direction of the panel holding portion 2 (Y direction). In the present description, such a shape in which the upper side of the tray supporting portion 16 is larger and the lower side is smaller is referred to as a reversely tapered shape. The tray supporting portion 16 is provided in a substantially lower half of the side plate 14 c of the supporting foot 14.

In the state in which the packaging trays 1 are stacked in a plurality of tiers, an upper surface 16 a of the tray supporting portion 16 is in contact with the first contact surface 14 b of the top tier tray 1T. Hereinafter, the upper surface 16 a of the tray supporting portion 16 that comes into contact with the first contact surface 14 b will be referred to as a third contact surface 16 a. That is, the tray supporting portion 16 includes the third contact surface 16 a to be in contact with the first contact surface 14 b of the top tier tray 1T.

FIG. 8 is a perspective view of the supporting foot 14 as seen from the lower surface side.

As illustrated in FIG. 8, the shape of the supporting foot 14 is substantially rectangular as seen in the normal direction of the bottom plate 18 (Z direction). Moreover, each of the four corners of a rectangle that is the shape of the supporting foot 14 is rounded into a curved surface and forms a first curved surface portion 14 r that is a curved surface (rounded surface) having a predetermined radius of curvature. More specifically, the first curved surface portions 14 r correspond to both ends of the second contact surface 15 b of the panel pressing portion 15 at a lower portion of the supporting foot 14 (an upper portion in FIG. 8).

Regarding existing packaging trays, when the packaging trays are stacked in a plurality of tiers, a panel pressing portion of an upper tier tray is in direct contact with the upper surface of a liquid crystal panel; thus, the liquid crystal panel held in one of the trays directly receives the load of trays placed above the one of the trays. In addition, no member for supporting the panel is provided immediately below the panel pressing portion. Therefore, the existing packaging trays have a problem in that, if the load exceeds the strength of the liquid crystal panels, defects such as fracture and chipping in the liquid crystal panels may occur. Moreover, the existing packaging trays have a problem in that, if the load is small, insufficient fixing of the liquid crystal panels may result in flaws and dust generation due to the movement of the liquid crystal panels, for example, during tray transportation.

To address the problems, the packaging tray 1 according to the present embodiment includes the tray supporting portion 16 disposed on the upper surface 14 a side of the supporting foot 14, and the tray supporting portion 16 receives the load of the top tier tray 1T when the packaging trays 1 are stacked in a plurality of tiers, as illustrated in FIG. 7. Thus, the load of the top tier tray 1T applied to the liquid crystal panel P is reduced. In addition, because the panel supporting portion 13 is provided near the panel pressing portion 15, the load applied by the panel pressing portion 15 to the liquid crystal panel P can be received by the panel supporting portion 13. Thus, the occurrence of defects in the liquid crystal panels P can be suppressed.

According to the configuration of the present embodiment, the second contact surface 15 b of the panel pressing portion 15 comes into contact with the upper corner of the peripheral portion of the liquid crystal panel P from the direction forming an angle of 45° to the upper surface of the liquid crystal panel P. The panel pressing portion 15 restricts the movement of the liquid crystal panel P in both vertical and horizontal directions. As a result, the movement of the liquid crystal panels P during transportation is less likely to occur; thus, flaws and dust generation of the liquid crystal panels P can be suppressed.

FIG. 10 illustrates a problem with a packaging tray 101 of a first comparative example.

The packaging tray 101 of the first comparative example does not include first curved surface portions at both ends of a panel pressing portion 115. In this case, of the upper surface of a liquid crystal panel P, stress is concentrated on areas Q that are in contact with the corners at both ends of the panel pressing portion 115, as illustrated in FIG. 10. Therefore, there is a higher probability that fracture of the liquid crystal panel P occurs near the areas Q.

On the other hand, FIG. 9 illustrates a function of the first curved surface portion 14 r according to the present embodiment.

As illustrated in FIG. 9, because the packaging tray 1 according to the present embodiment includes the first curved surface portions 14 r at both ends of the panel pressing portion 15, stress does not concentrate on a specific area of the liquid crystal panel P, and the stress applied by the panel pressing portion 15 to the liquid crystal panel P is dispersed appropriately. Thus, fracture of the liquid crystal panel P is less likely to occur.

The tray supporting portion 16 has a reversely tapered shape and can thus receive the load of the top tier tray 1T stably.

With the various above-described functions, the occurrence of defects in the liquid crystal panels P when a plurality of packaging trays 1 are stacked can be reduced using the packaging trays 1 according to the present embodiment.

Second Embodiment

Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. 11 to 14.

The basic configuration of a packaging tray according to the second embodiment is the same as that of the first embodiment. However, the configurations of a panel pressing portion and a tray supporting portion differ from those of the first embodiment.

FIG. 11 is a sectional view of the packaging tray according to the second embodiment. FIG. 12 is a sectional view illustrating a state in which three packaging trays are stacked in tiers. FIG. 13 is a perspective view of a supporting foot as seen from the lower surface side.

In FIGS. 11 to 13, components that are the same as those of the first embodiment are denoted by the same reference signs, and descriptions of such components are omitted.

As illustrated in FIGS. 11 to 13, in a packaging tray 21 according to the second embodiment, a panel pressing portion 25 includes a second contact surface 25 b and a first step portion 23 that is provided between a first contact surface 14 b and the second contact surface 25 b. That is, in the first embodiment, the first contact surface 14 b and the second contact surface 15 b form an angle θ of 45°. In contrast, in the second embodiment, the first contact surface 14 b and the second contact surface 25 b are parallel to each other, and the second contact surface 25 b is disposed at a position one step higher than the position of the first contact surface 14 b. Thus, the first contact surface 14 b and the second contact surface 25 b whose heights differ from each other compose the first step portion 23.

As illustrated in FIG. 12, two first step portions 23 are provided in such a manner that, in the lateral direction of a panel holding portion 22 (X direction), the distance D1 between the first step portions 23 is slightly larger than the width D2 of the liquid crystal panel P. Thus, in a state in which the packaging trays 21 are stacked in a plurality of tiers, the liquid crystal panel P is placed between the first step portions 23 on the left and right sides of a panel pressing portions 25 of a top tier tray 21T. In such a way, the second contact surface 25 b of the panel pressing portion 25 comes into contact with the upper surface of a peripheral portion of the liquid crystal plate P.

A supporting foot 14 includes a side wall surface 14 d rising from the second contact surface 25 b toward the panel supporting portion 13. The junction of the second contact surface 25 b and the side wall surface 14 d is rounded into a curved surface and to form a second curved surface portion 27 made up of a curved surface (rounded surface) having a predetermined radius of curvature.

The shape of a tray supporting portion 26 as seen in the longitudinal direction of the panel holding portion 22 (Y direction) is a trapezoid, and the long side of the trapezoid is at an upper position and the short side is at a lower position. That is, the shape of the tray supporting portion 26 is reversely tapered. The tray supporting portion 26 includes a third contact surface 26 a to be in contact with the first contact surface 14 b of the top tier tray 21T. As illustrated in FIG. 11, the outer dimension W3 on the upper side of the tray supporting portion 26 is relatively large, and the outer dimension W4 on the lower side is relatively small. As examples of the shapes of the tray supporting portion 26, a substantially semicircular shape is described in the first embodiment and a trapezoidal shape is described in the second embodiments. However, modifications are possible as appropriate without limitation to such shapes.

Other configurations of the second embodiment are similar to those of the first embodiment.

Also with the packaging tray 21 according to the second embodiment, the load applied by the top tier tray 21T to the liquid crystal panel P is reduced because the tray supporting portion 26 receives the load of the top tier tray 21T. In addition, because the panel supporting portion 13 is provided substantially directly below the panel pressing portion 25, the load applied by the panel pressing portion 25 to the liquid crystal panel P can be received by the panel supporting portion 13. Thus, an advantageous effect similar to that of the first embodiment, that is, an advantageous effect in which the occurrence of defects such as fracture and chipping in the liquid crystal panels P can be suppressed is attained.

FIG. 14 illustrates a problem with a packaging tray 201 of a second comparative example.

The packaging tray 201 of the second comparative example differs from the packaging tray 21 according to the second embodiment in that the packaging tray 201 does not have a first step portion 23 and a second curved surface portion 27. Accordingly, a first contact surface 214 b of a supporting foot 214 is a flat surface and comes into contact with a liquid crystal panel P together with a tray supporting portion 216, thus functioning as a panel pressing portion. In the configuration of the packaging tray 201 of the second comparative example, the rigidity of a side plate 214 c of the supporting foot 214 tends to be higher, compared with that of the present embodiment. Therefore, relatively high pressure is applied by the first contact surface 214 b to the liquid crystal panel, and stress concentrates especially on an area Q that is in contact with a corner of the supporting foot 214. As a result, fracture of the liquid crystal panel P is likely to occur near the area Q.

In contrast, in the packaging tray 21 according to the second embodiment, the panel pressing portion 25 includes the first step portion 23. Thus, the flexibility of the panel pressing portion 25 increases as the rigidity of the side wall surface 14 d of the supporting foot 14 decreases, compared with the packaging tray 201 of the second comparative example without any step portions. In addition, the second curved surface portion 27 is provided at the junction of the second contact surface 25 b and the side wall surface 14 d.

These configurations enable the panel pressing portion 25 according to the second embodiment to press the liquid crystal panel P in a flexible manner, without causing stress concentration on a specific area of the liquid crystal panel P. Therefore, if the packaging tray 21 receives an impact, for example, during transportation, the panel pressing portion 25 can be easily deformed to relieve the impact. Accordingly, the packaging tray 21 can hold the liquid crystal panels P stably.

Other advantageous effects such as the effect produced by providing first curved surface portions 14 r at both ends of the panel pressing portion 25 and the effect produced by forming the tray supporting portion 26 into a reversely tapered shape are similar to those of the first embodiment.

Third Embodiment

Hereinafter, a third embodiment of the present invention will be described with reference to FIGS. 15 to 16.

The basic configuration of a packaging tray according to the third embodiment is the same as that of the second embodiment; however, the configuration of a panel pressing portion differs from that of the second embodiment.

FIG. 15 is a sectional view of the packaging tray according to the third embodiment. FIG. 16 illustrates a function of a second step portion.

In FIGS. 15 to 16, components that are the same as those of the second embodiment are denoted by the same reference signs, and descriptions of such components are omitted.

As illustrated in FIG. 15, in a packaging tray 31 according to the third embodiment, a panel pressing portion 35 includes a second contact surface 35 b, a first step portion 33, a noncontact surface 35 e that is continuous from the second contact surface 35 b and that does not come into contact with a liquid crystal panel P, and a second step portion 34 provided between the second contact surface 35 b and the noncontact surface 35 e. The panel pressing portion 35 according to the third embodiment differs from the panel pressing portion 25 according to the second embodiment in that the panel pressing portion 35 includes the noncontact surface 35 e and the second step portion 34.

As illustrated in FIG. 16, noncontact surfaces 35 e are provided at both ends of the second contact surface 35 b extending in the longitudinal direction of a panel holding portion (Y direction) and are disposed at positions higher than the position of the second contact surface 35 b (lower positions in FIG. 15). Thus, the noncontact surface 35 e and the second contact surface 35 b whose heights differ from each other compose the second step portion 34.

Other configurations are similar to those of the second embodiment.

Also with the packaging tray 31 according to the third embodiment, the load applied by a top tier tray to a liquid crystal panel P is reduced because the tray supporting portion 26 receives the load of the top tier tray. In addition, because the panel supporting portion 13 is provided substantially directly below the panel pressing portion 35, the load applied by the panel pressing portion 35 to the liquid crystal panel P can be received the panel supporting portion 13. Thus, an advantageous effect similar to that of the first and second embodiments, that is, the advantageous effect in which the occurrence of defects such as fracture and chipping in the liquid crystal panels P can be reduced is attained.

Moreover, in the case of the third embodiment, as illustrated in FIG. 16, the panel pressing portion 35 includes the second step portion 34 between the noncontact surface 35 e and the second contact surface 35 b in addition to the first step portion 33 between a first contact surface 14 b and the second contact surface 35 b. Accordingly, the panel pressing portion 35 has higher flexibility compared with the packaging tray 21 according to the second embodiment without the second step portion 34. Thus, the packaging tray can hold the liquid crystal panel P with further stability.

Other advantageous effects such as the effect produced by providing first curved surface portions 14 r at both ends of the panel pressing portion 35 and the effect produced by forming the tray supporting portion 26 into a reversely tapered shape are similar to those of the first and second embodiments.

The technical scope of the present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit of the present invention.

For example, the shape of the tray supporting portion is reversely tapered in the above-described embodiments; however, the shape of the tray supporting portion is not necessarily reversely tapered and may or not be tapered. In addition, the number, shape, disposition, dimensions, material, and the like of each component composing the packaging tray may be modified as appropriate.

Moreover, the packaging trays for holding a plurality of small liquid crystal panels are taken as examples in the above-described embodiments; however, the present invention may be applied to a packaging tray for holding a large liquid crystal panel, for example. Furthermore, the present invention is not limited to packaging trays for liquid crystal panels and may be applied to packaging trays for other kinds of display panels such as organic electroluminescent (EL) panels.

INDUSTRIAL APPLICABILITY

An aspect of the present invention can be applied to packaging trays for packaging various kinds of display panels such as liquid crystal panels and organic EL panels.

REFERENCE SIGNS LIST

-   -   1, 21, 31 packaging tray     -   1T, 21T top tier tray     -   1B, 21B bottom tier tray     -   2, 22 panel holding portion     -   12 holding recess     -   13 panel supporting portion     -   14 supporting foot     -   14 b first contact surface     -   14 d side wall surface     -   15, 25, 35 panel pressing portion     -   15 b, 25 b, 35 b second contact surface     -   16, 26 tray supporting portion     -   16 a, 26 a third contact surface     -   18 bottom plate     -   23, 33 first step portion     -   34 second step portion     -   35 e noncontact surface     -   P liquid crystal panel (display panel) 

1. A packaging tray that is capable of holding at least one display panel and that is stackable in a plurality of tiers, comprising: at least one panel holding portion, wherein the panel holding portion includes a holding recess that holds the display panel, a panel supporting portion that protrudes to a position above a bottom plate of the holding recess and that comes into contact with a lower surface of the display panel to support the display panel, a supporting foot protruding to a position below the bottom plate of the holding recess, a panel pressing portion provided in the supporting foot, and a tray supporting portion provided on an upper surface side of the supporting foot, and wherein, in a state in which the display panel is held in the holding recess, a top tier tray having a shape of the packaging tray is stacked above the packaging tray, and a bottom tier tray having the shape of the packaging tray is stacked below the packaging tray, the supporting foot includes a first contact surface that is in contact with the tray supporting portion of the bottom tier tray, the panel pressing portion includes a second contact surface that is in contact with the display panel held in the bottom tier tray, and the tray supporting portion includes a third contact surface that is in contact with the first contact surface of the top tier tray.
 2. The packaging tray according to claim 1, wherein the panel supporting portion is disposed at a position where the panel supporting portion comes into contact with a peripheral portion of the display panel from below, and wherein the panel pressing portion is disposed at a position where the panel pressing portion comes into contact with the peripheral portion of the display panel from above.
 3. The packaging tray according to claim 2, wherein the second contact surface is provided so as to incline with respect to the first contact surface and comes into contact with an upper corner of the peripheral portion of the display panel.
 4. The packaging tray according to claim 2, wherein the panel pressing portion further includes a first step portion provided between the first contact surface and the second contact surface, and wherein the second contact surface comes into contact with an upper surface of the peripheral portion of the display panel.
 5. The packaging tray according to claim 4, wherein the supporting foot further includes a side wall surface rising from the second contact surface toward the panel supporting portion, and wherein a junction of the second contact surface and the side wall surface is rounded into a curved surface.
 6. The packaging tray according to claim 4, wherein the panel pressing portion further includes a noncontact surface that is continuous from the second contact surface and that does not come into contact with the display panel and a second step portion that is provided between the second contact surface and the noncontact surface.
 7. The packaging tray according to claim 1, wherein a shape of the supporting foot as seen in a normal direction of the bottom plate is a rectangle, and wherein corners of the rectangle that is the shape of the supporting foot are rounded into curved surfaces.
 8. The packaging tray according to claim 1, wherein an outer dimension of an upper side of the tray supporting portion is relatively large, and an outer dimension of a lower side of the tray supporting portion is relatively small. 